A novel neutralization sensitive and subdominant RAP-1-related antigen (RRA) is expressed byBabesia bovismerozoites

Abstract

B. bovis express a novel subdominant RAP-1-like molecule that may contribute to erythrocyte invasion and/or egression by the parasite.

Serological and molecular diagnostic surveys combined with examining hematological profiles suggests increased levels of infection and hematological response of cattle to babesiosis infections compared to native buffaloes in Egypt

“…The aim of the present study is to estimate the presence of bovine and buffaloes babesiosis in distinct populations in Egypt using blood smear examination, competitive inhibition ELISA and novel PCR procedures based on the amplification of the recently identified and highly conserved rhoptry associated protein ( rap)-1c gene of B. bigemina [25] and rap-1 related antigen ( rra) gene of B. bovis [26]. We also compared Babesia -associated hematological alterations in the cattle and buffalo populations sampled in this study.…”

Identification and Characterization of the RouenBd1987 Babesia divergens Rhopty-Associated Protein 1

“…The limited growth inhibition observed suggests the binding of BdRAP-1 to the RBC receptor during invasion is not the primary pathway this species uses to invade host cells, or,, there is significant redundancy in the invasion mechanisms and multiple invasion pathways are available to the parasite. Additionally, the full repertoire of RAP-1 and other RAP-1 related molecules in the parasite genome has not been accounted for, as it has in other Babesia species [32]–[35], and thus, homologs of this antigen may serve in its role when BdRAP-1 is neutralized by antibodies. It seems increasingly likely that RAP-1 in malaria may not directly play a role in the invasive process, but like other proteins housed in the rhoptry bulb, may participate in events downstream of active entry, like enhancing parasite survival in the host cell [36]–[38].…”

Emerging perspectives in the research of bovine babesiosis and anaplasmosis

“…Research performed in Plasmodium demonstrated that replacing one of two ef-1˛ genes present in malaria parasites by homologous recombination using transfection techniques would not greatly affect parasite viability (Janse et al, 2003). These observations provided rationale for the use of the ef-1˛ locus as a target of integration for the development of a B. bovis stable transfection system (Suarez and McElwain, 2010;Janse et al, 2003). The successfully transfected parasites were selected with antibiotic blasticidin, and they were able to express abundant and intracellular, cytoplasmic, green fluorescent (GFP-BSD) protein ( Fig.…”

“…In addition, transfection methods, which allow the incorporation and expression of foreign DNA into Babesia, are also useful for characterizing gene function, for studying mechanisms of gene regulation by using gene knock-out and supplementation strategies, and for vaccine development. A recent review described the development and potential applications of Babesia transient and stable transfection systems in more depth (Suarez and McElwain, 2010). Briefly, the transient transfection system has potential to be used for experiments requiring short term expression of the gene of interest, which in general are selectable markers (i.e.…”

“…Significant factors currently affecting the control of babesiosis and anaplasmosis include increased resistance to acaricides by ticks (Rosario-Cruz et al, 2009;Jonsson et al, 2008), and the numerous drawbacks of the current live vaccines (De Waal and Combrink, 2006;De Vos and Bock, 2000;Kocan et al, 2010). Whole genome sequencing of Babesia and Anaplasma organisms together with the development of novel research tools allowing genetic transformation are providing new insights on their genetics (Brayton et al, , 2007Felsheim et al, 2010;Herndon et al, 2010;Suarez and McElwain, 2010). Yet, despite of these advances, the most important limitations for developing improved control tools against these are the numerous and significant gaps in our understanding of the biology of Babesia and Anaplasma, and in the protective immune responses that they can elicit in cattle.…”